1. Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
2. University of Texas at Austin, Austin, Texas 78705, USA
3. General Atomics, San Diego, California 92121, USA
4. Lawrence Livermore National Laboratory, Livermore, California 94550, USA
5. University of Wisconsin at Madison, Madison, Wisconsin 53706, USA
6. Swiss Plasma Center, Ecole Polytechnique Fédérale de Lausanne, Lausanne VD 1015, Switzerland
7. University of California at Los Angeles, Los Angeles, California 90095, USA